The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingTerminals of ecu
Check sliding roof drive gear subassembly (sliding roof ecu)
Disconnect the p6 ecu connector.
Measure the resistance and voltage of the wire
harness side connector.
Reconnect the p6 ecu connector.
Measure the voltage of the connector.
If the result is not as speci ...
Disassembly
Remove no. 1 Side defroster nozzle duct
Remove the 3 screws and duct.
Remove no. 2 Side defroster nozzle duct
Remove the 3 screws and duct.
Remove no. 1 Heater to register duct
Remove the screw and duct.
Remove no. 2 Heater to register duct
...
Oil pump
Components
Removal
Remove chain sub-assembly
Remove the chain (see page em-22).
Remove oil pump assembly
Remove the 3 bolts, oil pump and gasket.
Disassembly
Remove oil pump strainer
Remove the 2 nuts, oil pump strainer and gasket.
...